This invention relates to a novel and improved one-step process for preparing .alpha.-(trichloromethyl)carbinols via a base-catalyzed condensation reaction of benzaldehydes and chloroform. One of the compound prepared via this process, Trichloromethyl-3-nitrobenzyl alcohol is a key intermediate useful in the preparation of a class of anthelmintic disulfonamide compounds, in particular, the process for preparing 4-amino-6-(trichloroethenyl)-1,3-benzenedisulfonamide also referred to as clorsulon is disclosed in U.S. Pat. No. 4,500,736. The anthelmintic compounds referred to herein are disclosed in U.S. Pat. No. 4,064,239 and are particularly useful against liver fluke in sheep and cattle.